NOVEL NEXT Vol 2 Chapter 74: Theodore Maiman Program
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If a piece of activated matter is placed in an optical resonator composed of two parallel mirrors (at least one of which is partially transmissive), particles at high energy levels will produce spontaneous emission in various directions.
Among them, the non-axially propagating light wave quickly escapes outside the resonator: the axially propagating light wave can propagate back and forth in the cavity, and when it propagates in the laser material, the light intensity increases continuously.
If the single-pass small-signal gain G0l in the resonant cavity is greater than the one-pass loss δ (G0l is the small-signal gain coefficient), self-excited oscillation can occur.
The motion state of an atom can be divided into different energy levels. When an atom transitions from a high energy level to a low energy level, it will release photons of corresponding energy (so-called spontaneous emission).
In 1951, American physicist Charles Harder Townes imagined that if you use molecules instead of electronic circuits, you can get radio waves with sufficiently small wavelengths.
Molecules have a variety of different vibrational forms, and some molecules have vibrations that are exactly the same as radiation in the microwave band.
But the question is how to convert these vibrations into radiation.
In the case of the ammonia molecule, under the right conditions, it vibrates 24,000,000,000 times per second (24 GHz), so it is possible to emit microwaves with a wavelength of 1.25 cm.
He imagined pumping energy into ammonia molecules through heat or electricity to make them in an "excited" state.
Then, imagine exposing these excited molecules to a microwave beam with the same natural frequency as the ammonia molecule—the energy of this beam can be very weak.
A single ammonia molecule is subjected to the action of this microwave beam, releasing its energy in the form of a beam of the same wavelength, which in turn acts on another ammonia molecule, causing it to release energy as well.
This very weak incident microwave beam is equivalent to the promotion of an avalanche by the standing point, and finally a strong microwave beam will be generated.
And the energy originally used to excite the molecule is all converted into a special kind of radiation.
In December 1953, Townes and his student Arthur Shallow finally made a device that worked on the above principles, producing the required microwave beams.
This process is called "microwave amplification of stimulated radiation". Its English acronym is M.A.S.E.R, from which the word "maser" is coined (such words are called acronyms and are increasingly used in technical terms).
In 1958, American scientists Schawlow and Townes discovered a magical phenomenon: when they illuminated a rare earth crystal with light emitted by a neon light bulb, the molecules of the crystal would emit bright, bright colors. Strong light that always comes together.
Based on this phenomenon, they proposed the "laser principle", that is, when a substance is excited by the same energy as its molecular natural oscillation frequency, it will produce this kind of non-divergent strong light-laser.
They published important papers on this and won the Nobel Prize in Physics in 1964.
On May 15, 1960, Maiman, a scientist at Hughes Laboratory in California, announced that he had obtained a laser with a wavelength of 0.6943 microns, which was the first laser ever obtained by human beings, and Maiman became the world's first laser. Scientists who brought lasers to practical use.
On July 7, 1960, Theodore Maiman announced the birth of the world's first laser.
Maiman's solution was to use a high-intensity flash tube to excite the ruby. Since ruby is actually just corundum doped with chromium atoms, when ruby is stimulated, it emits a red light.
A hole is drilled in the surface of a mirrored ruby, allowing red light to escape from the hole, creating a fairly concentrated and thin column of red light that, when directed at a point, reaches a distance greater than the surface of the sun. high temperature.
And the former Soviet scientist Nikolai Basov also invented the semiconductor laser in 1960.
The structure of semiconductor laser is usually composed of p-layer, n-layer and active layer forming double heterojunction.
Its characteristics are: small size, high coupling efficiency, fast response speed, wavelength and size adapted to the fiber size, direct modulation, and good coherence.
The energy of a photon is calculated as E=hv, where h is Planck's constant and v is the frequency. It can be seen that the higher the frequency, the higher the energy. Laser frequency range 3.846×10^(14)Hz to 7.895×10^(14)Hz.
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Zhou Wenwen used rubies, so of course he used Theodore Maiman's plan, and Zhou Wenwen only needed to replace the projectile and time.
So after more than 2 minutes
Chapter 75 Announcement of the beam saber